My park plan normally is Harry Potter first thing, Upper Lot Rides, Studio Tour, then Lower Lot starting with Jurassic Park, and then finish off with Shrek at the end. Is it better to go to the Lower Lot first and then going back to the Upper Lot?
I'd say that your park plan probably works better than starting at the Lower Lot, as Harry Potter's wait times can increase from around 5 minutes to 50 minutes in only an hour. It might be better to go on the Lower Lot rides before the Studio Tour sometimes, but I'd only say that for busier days at the park. Overall, if your park plan works for you now, then I would stick with it.
It depends - if you're able to hit Early Entry, you can knock a lot of the rides out pretty easily once you finish Potter. Lower Lot then Upper Lot would be my bet, followed by the Studio Tour and shows.